WhatsApp is always ahead in providing best-in-class features to its users. Now, WhatsApp is working on "Message Reactions" just like we see on other messaging or social media applications such as Messenger, Instagram, Facebook, etc.
This feature is finally on its way to WhatsApp, as has been revealed today. The company is seemingly testing it with a very small circle of users. The screenshot above originates from someone who saw that message, clearly intended as a test.
As always, as soon as the message reaction for WhatsApp is released you need to be on the latest version of WhatsApp. Currently, this feature is yet to roll out in beta channels, so there is an unclear date by which WhatsApp would be going to make it available for the public. WhatsApp sometimes tests new features like this for many, many months before it deems them worthy of a release. So, for now, hang tight, knowing that one of the most requested features is actually being worked on.